Process of making metallic films or flakes.



7 To all whom it may concern.-

UNITED STATES PATENT OFFICE.

THOMAS A: EDISON, OF LLEW ELLYN- 'PARK, NEW JERSEY, ASSIGNOR TO EDISONSTORAGE BATTERY COMPANY, OF WEST ORANGE, NEW JER- SEY, A CORPORATIONOF-NEW JERSEY.

Specification of Letters Patent.

Patented May 29, 1906.

Application and seat so. not. Serial-Ho. 262.982.

wherein the active mass, such as nickel h droxid, is admixed withinsoluble metal '0' scales or films for the purpose of insuring contactbetween the active particles themselves and between the active particlesand the in closing pockets .or other metallic supports. As I havepointed-out, these metallic scales or films are formed, preferably, ofcobaltnickel alloy, since by using this material the characteristicallygood contact'obtained with cobalt is secured, while the presence of thenickel prevents the cobalt from suffering more than a mere surfaceoxidation.

'My present invention relates to an improved process by which metallicscales or films can be obtained at low cost, either of co- I balt or ofnickel, or of a cobalt-nickel alloy.

I nickel and j thousandth of an inch in thickness and I a pearingpractically as a mere blush upon tl ie copper srrface) This zinc isdeposited'on the copper or nickel in a solution of zinc sulfate or otherzinc salt in the usual wa The cathode thus prepared is now washe and ina suitable electrolytic bath a film of the desiredmetal or metals isplated on the electrodeposited layer of zinc. When either cobalt ornickel is to be deposited a suitable ammomum-sulfate solution of thatmetal and cogbalt or nickel anodes are used. When both metals are to besimultaneously deposited, a cobalt-nickel ammonium-sulfate solution isemployed with se arate cobalt. and nickel anodes. In the la ter case thecurrent from each anode will be sore ated as to secure the desiredproportion o deposit thereof. I .havefound in practice that good resultsare or oil, the latter be]? secured when the deposited alloy is composedof about seventy er cent. of cobalt and thirty percent. of nic el,although these proportfons may be very widely varied. The cobelt ornickel or cobalt-nickel film thus def posited upon the superposed filmof zinc is made extremely thin generally about .0002 inch in thickness.he cathode is now immersed in a dilute acid (sulfuric, hydrochloride, oracetic) which does not sensibly attack the cobalt or nickel orcobalt-nickel film, but results in a relatively rapid dissolution of thezinc to thereby free the insoluble film from the'metal base. Themetallic zinc .in being thus attacked by the weak acid solution resultsin the formation of hydrogen gas, which in esca ing eifects a separationor detachment 0 the nickel or cobalt or alloy film. I find, furthermore,that by carrying on the process described the film of cobalt or nickelor alloy thereof becomes detached in the form of small flakes or scales,which naturally assume a curved or curled shape-a phenomenon especiallycharacteristic of cobaltand which afterbreakin up andsizing by screensare thereforein the best condition for admixture with the activematerial. These films are now washed and annealed by heating them in ahydrogen atmosphere to a red heat, which treatment effects a veryperfect cleaning of tlie surfaces. Films or scales obtained in this waymay be applied to the active material in any suitable manner, examplesof which are indicated in my concurrent applications for Letters'Patent.4

In order to facilitate the stripping of the deposited film of cobalt ornic el or allo thereof, it may in some cases be desirable a ter the filmor blush of zinc has been deosited-on the copper plate to immerse theatter in a solution-of wax or oil (such as solvent so that when dry thezinc enou h as not to e. prevent the roper eposition o the cobalt ;ornickel or a loy thereof by greatly facilitat .i thestripp operatlon.avmg-now escrlbed my invention, what I claim as new therein, and desireto secure by Letters Patent, is as follows:@

1. The process of making metallic films,

which consists in depositing a soluble metal on a cathode, then inelectrodepositing a film of an'insoluble metal or metals thereon, and

. in finally dissolving the soluble metal to detach the insoluble film,substantially as set forth.

2. The process of making metallic films, which consists in depositing asoluble metal on a cathode, then in electrodepositing a film ofinsoluble metal or metals thereon and finally immersing the latedcathode in an acid-bath to attack t e soluble metal and separate theinsoluble film, substantially as set forth.

3. The process of making metallic films, which consists in depositing asoluble metal on a suitable cathode, in electrodepositing an insolublemetallic film thereon, and in subj ecting the plated cathode to theeffect of the acid which dissolves the insoluble metal and results inthe evolution of gas to separate and detach the insoluble film,substantially as set forth.

4. The process of making metallic films,

which consists in de ositing a thin film of zinc on a suitable cat ode,in electrodepositing an insoluble film on the zinc, and in subjectingthe plated cathode to dilute acid to dissolve the zinc and generatehydrogen gas,

as and for the purposes set forth.-

5. The process of making metallic films, which consists in depositinga'soluble metallic film on a-suitable cathode, in electrode ositmgthereon a thin film of metallic coba t or cobalt alloy and in dissolvingthe soluble metal to detach the insoluble film, substantially as setforth.

6. The process of making metallic films, which consists in de ositing a"thin film of zinc on a suitable cat ode, in electrodepositing thereon athin film of cobalt or cobalt al- 10 and in subjecting the platedcathode to dilute acid to thereby dissolve the zinc and effect theseparation of the insoluble film, substantially as setforth.

7. The process of making metallic films, which consists in depositing asoluble metallic film on a suitable cathode, in electrodepo sitingthereon a thin film of metallic coba t or cobalt ,allo and in dissolvingthe soluble metal to etach the insoluble film, andfi'a finally annealingthe separated film in a big drogen atmosphere, substantially as set fort8. The process of making metallic films, which consists in de 'ositing athin film of zinc'on a suitable cat ode, in electrodepositing thereon athin film of cobalt or cobalt allo and in subjecting the plated cathodeto dilute acid to thereby dissolve the zinc and effect the separation ofthe insoluble film, and v in finally annealing the separated film in ahydrogen atmosphere, as and for the pur-' poses set forth.

This specification signed and witnessed this 29th-d'ay of March, 1905.

- THOMAS A. EDISON. Witnesses:

FRANK L. DYER, ANNA R. KLEnM.

